Cyber Resilience

CVE-2025-9090

Command Injection in Tenda Ac20 Firmware 16.03.08.12

Public PoCCommand Injection
Published
17 August 2025
Modified
17 June 2026
Patch / advisory
View advisory
CVSS Score v4 2.1
Click a component to see what it means
Raw vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.14 96th percentile
Risk Priority 45 floored blend · peak EPSS

Summary

CVE-2025-9090 is a low-severity Injection (CWE-74) vulnerability in Tenda Ac20 Firmware. Its CVSS base score is 2.1 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked in the top 4% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

A vulnerability identified as CVE-2025-9090 affects the Tenda AC20 router running firmware 16.03.08.12. It resides in the websFormDefine function within the /goform/telnet file of the Telnet Service component. The issue stems from improper handling of input that permits command injection, as classified under CWE-74 and CWE-77.

The flaw can be exploited remotely by an authenticated user with low privileges. Successful manipulation allows an attacker to inject and execute arbitrary commands, resulting in limited impacts to confidentiality, integrity, and availability on the affected device. A proof-of-concept exploit has been publicly disclosed via GitHub and is available for use.

The EPSS score for this CVE rose from a low baseline to a peak of 0.0924 on 2025-12-18 before receding to the current value of 0.0368, indicating emerging exploitation interest after disclosure. The provided references consist of public vulnerability database entries and exploit details but contain no information on official patches or mitigation steps.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

A vulnerability was identified in Tenda AC20 16.03.08.12. Affected is the function websFormDefine of the file /goform/telnet of the component Telnet Service. The manipulation leads to command injection. It is possible to launch the attack remotely. The exploit has been…

more

disclosed to the public and may be used.

CWE(s)
CWE-74CWE-77

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1221 Template Injection Stealth
Adversaries may create or modify references in user document templates to conceal malicious code or force authentication attempts.
attack.mitre.org →
T1659 Content Injection Initial Access
Adversaries may gain access and continuously communicate with victims by injecting malicious content into systems through online network traffic.
attack.mitre.org →
T1674 Input Injection Execution
Adversaries may simulate keystrokes on a victim’s computer by various means to perform any type of action on behalf of the user, such as launching the command interpreter using keyboard shortcuts, typing an inline script to be executed,…
attack.mitre.org →
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-7415Same vendor: Tenda
CVE-2026-5339Same vendor: Tenda
CVE-2026-1689Same vendor: Tenda
CVE-2026-0581Same vendor: Tenda
CVE-2026-7469Same vendor: Tenda
CVE-2025-15048Same vendor: Tenda
CVE-2025-5836Same vendor: Tenda
CVE-2026-1638Same vendor: Tenda
CVE-2025-4357Same vendor: Tenda
CVE-2025-5763Same vendor: Tenda

Affected Assets

tenda
ac20 firmware
16.03.08.12

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.1
  • V1.2.3
  • V1.2.5
  • V1.2.8

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover command-construction flaws before deployment.

SI-10 Information Input Validation good match

SI-10 directly requires validation of information inputs to reject malformed or special-element content before it reaches downstream parsers.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles include proper neutralization and safe command construction practices.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly require input validation and output encoding that prevent injection flaws.

DE.CM-09 partial match
prevents

Runtime monitoring of software and data can detect anomalous command execution resulting from injection.

ID.RA-01 partial match
prevents

Identifying recorded vulnerabilities enables remediation of command-injection flaws before exploitation.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.28 Secure coding mostly match
prevents

Secure coding standards require proper escaping and parameterization of commands, directly eliminating CWE-77.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development catches injection vulnerabilities before release.

A.8.15 Logging partial match
finds

Logging supports detection of injection attempts but does not prevent the weakness.

A.8.16 Monitoring activities partial match
finds

Monitoring activities can identify active injection attacks after they occur.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and output encoding that directly prevent injection flaws.

A.8.26 Application security requirements partial match
prevents

Application security requirements explicitly call for controls against injection attacks in software design.

References